Light-Guide Plate Transparent Textured Ink Micro-Lens Extraction
Solution Overview
Problem
Existing light-guide devices for illumination and display purposes face inefficiencies in light extraction due to the use of white ink dots, which absorb rather than reflect light, and high costs associated with refractive features produced through injection moulding or machining.
Innovation Solution
A method of manufacturing light-guide apparatus with transparent textured ink printed onto the surface to form micro-lens-like extraction features, providing an uneven and irregular surface for refractive light exit, using screen printing and UV curing to achieve controlled and efficient light extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If white ink dots are used to reflect light from the light guide, then the manufacturing cost is low, but the light extraction efficiency is poor due to absorption
Solution Approach 1:
The invention changes the optical parameter of the extraction features from reflective (white ink) to refractive (transparent material with varying refractive index). The transparent extraction features utilize refraction rather than reflection to extract light, eliminating absorption losses while maintaining low manufacturing cost through screen printing and UV curing processes.
Solution Approach 2:
The invention uses a composite structure combining transparent extraction features made of transparent material with the light guide plate. The transparent extraction features have a different refractive index than the light guide plate, creating the necessary optical contrast for efficient light extraction without the absorption problems of white ink.
2Loss of energy
If injection moulding or machining is used to create refractive features, then the light extraction efficiency is improved, but the manufacturing cost increases
Solution Approach 1:
The invention replaces mechanical machining or injection moulding processes with a printing-based approach. Screen printing and UV curing are used to deposit transparent extraction features directly onto the light guide plate surface, eliminating the need for expensive mechanical tooling and machining operations while achieving comparable or superior light extraction efficiency.
Solution Approach 2:
The invention changes the manufacturing method from subtractive (machining) or high-tooling-cost processes (injection moulding) to an additive printing process. This parameter change in the manufacturing approach dramatically reduces tooling costs and setup expenses while maintaining the optical performance of refractive extraction features.
3Loss of energy
If mechanical machining or laser machining is used to create extraction features, then the light extraction function is achieved, but the surface roughness is very high
Solution Approach 1:
The invention replaces mechanical and laser machining processes with a printing-based deposition method. Screen printing followed by UV curing creates smooth extraction features without the high surface roughness inherent in mechanical machining or laser ablation, achieving better optical quality and light extraction uniformity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method enhances light extraction efficiency and uniformity across the light-guide, reducing production costs by eliminating the need for additional coatings and achieving high aspect ratios for micro-lens-like elements, resulting in improved optical properties and reduced visibility of extraction features.
Implementation Method 1
light rays passing through the light extraction features that are incident upon the uneven, irregular exterior surface are refracted out of the light-guide apparatus
Implementation Method 2
curing the transparent textured ink to form light extraction features consisting of the transparent textured ink
Data Source
Figure 1~2
Figure 3~4
Figure 5(a)~5(c)
AI summary
A light-guide apparatus comprising a light-guide plate for guiding light rays and a plurality of light extraction features is described. The light extraction features comprise a transparent material applied to the light-guide plate so as to form an uneven surface. The transparent material may comprise a textured ink applied to the surface of the light-guide plate via a printing process. The incorporation of an uneven surface provides mirco-lens like elements on the surface of the extraction feature which have a higher aspect ratio and so lend themselves to the refraction of the light out of the light-guide plate. In this way a device is produced wherein the size, height, location and surface profile of the extraction features can be carefully controlled. As a result the described light-guide apparatus provides for a highly efficient and relatively uniform light output.